.eleventy.js

const govukEleventyPlugin  = require('@x-govuk/govuk-eleventy-plugin')
const { DateTime } = require("luxon");
const childProcess = require('child_process');
const fs = require("fs");
const path = require("path");

function injectGitSha(eleventyConfig, gitHubRepositoryUrl) {
    let latestGitCommitHash = process.env.GITHUB_COMMIT_SHA;

    if(!latestGitCommitHash) {
        try {
            latestGitCommitHash = childProcess.execSync('git rev-parse HEAD').toString().trim();
        } catch (e) {
            console.warn("Unable to determine current Git commit hash. Permalinks will not be generated.")
            return;
        }
    }

    eleventyConfig.addGlobalData(
        'gitHashPath',
        gitHubRepositoryUrl + '/blob/' + latestGitCommitHash + '/docs'
    );
}

module.exports = function(eleventyConfig) {
    const _siteRoot = process.env.SITE_ROOT ?? 'http://localhost/';
    const gitHubRepositoryUrl = "https://github.com/UKHomeOffice/engineering-guidance-and-standards";

    // Pass assets through to final build directory
    eleventyConfig.addPassthroughCopy({ "docs/assets/logos": "assets/logos"});
    // Register the plugins
    let govukPluginOptions = {
        scssSettingsPath: "/styles/_settings.scss",
        icons: {
            mask: '/assets/logos/ho-mask-icon.svg',
            shortcut: '/assets/logos/ho-favicon.ico',
            touch: '/assets/logos/ho-apple-touch-icon.png'
        },
        opengraphImageUrl: '/assets/logos/ho-opengraph-image.png',
        homeKey: 'Home',
        header: {
            logotype: {
                html:
                    '<span class="govuk-header__logotype">' +
                    '  <img src="/assets/logos/ho_logo.svg" height="34px" alt="Home Office Logo">' +
                    '  <span class="govuk-header__logotype-text">Home Office</span>' +
                    '</span>'
            },
            productName: 'Engineering Guidance and Standards',
            organisationName: 'Home Office',
            search: {
                label: 'Search site',
                indexPath: '/search.json',
                sitemapPath: '/sitemap.html'
            }
        },
        footer: {
            copyright: {
                html: '© <a class="govuk-footer__link" href="https://github.com/UKHomeOffice/engineering-guidance-and-standards/blob/main/LICENCE">Crown Copyright (Home Office)</a>'
            },
            meta: {
                items: [
                    {
                        href: '/about/',
                        text: 'About'
                    },
                    {
                        href: '/cookies/',
                        text: 'Cookies'
                    },
                    {
                        href: '/accessibility-statement/',
                        text: 'Accessibility'
                    },
                    {
                        href: gitHubRepositoryUrl,
                        text: 'GitHub repository'
                    }
                ]
            }
        },
        stylesheets: ['/styles/base.css'],
    };
    eleventyConfig.addPlugin(govukEleventyPlugin, govukPluginOptions)

    // Customise markdown-it renderer provided by x-gov 11ty plugin. Plugin execution is
    // deferred, so this needs to be a plugin, and added after the x-gov plugin is.
    eleventyConfig.addPlugin((eleventyConfig) => {
        const md = require('@x-govuk/govuk-eleventy-plugin/lib/markdown-it.js')(govukPluginOptions)

        md.use(require('./lib/markdown/dl-as-govuk-summary-list'));

        eleventyConfig.setLibrary('md', md);
    });

    eleventyConfig.addFilter("postDate", (dateObj) => {
        return DateTime.fromJSDate(dateObj).toFormat('d MMMM yyyy');
    });

    // Used for tag page generation
    eleventyConfig.addFilter("getAllTags", collection => {
      let tagSet = new Set();
      for(let item of collection) {
          (item.data.tags || []).forEach(tag => tagSet.add(tag));
      }
      return Array.from(tagSet).sort(function(a, b) {
        return a.localeCompare(b); // sort by tag name
      });
    });

    eleventyConfig.addFilter("filterTagList", function filterTagList(tags) {
        // Tags in array are ignored, no tag list page is generated for these
        return (tags || []).filter(tag => ["homepage"].indexOf(tag) === -1);
    });

    eleventyConfig.addFilter("orderPagesByTitle", function orderByTitle(collection) {
      return collection.sort(function(a, b) {
        return a.data.title.localeCompare(b.data.title); // sort by title ascending
      });
    });

    fs.readdirSync(path.join(process.cwd(), path.join('lib', 'filters'))).map((file) => path.parse(file))
        .filter(({ext}) => ext === '.js')
        .forEach(({name, base}) =>
            eleventyConfig.addFilter(
                name,
                require(path.join(process.cwd(), 'lib', 'filters', base)),
            )
        );

    eleventyConfig.addCollection("homepageLinks", function(collectionApi) {
      return [
          ...collectionApi.getFilteredByGlob(["**/principles.md"]),
          ...collectionApi.getFilteredByGlob(["**/standards.md"]),
          ...collectionApi.getFilteredByGlob(["**/patterns.md"]),
      ];
    });

    eleventyConfig.addCollection("getAllStandardsOrderedByID", function(collectionApi) {
      return collectionApi.getFilteredByGlob("**/standards/*.md").sort(function(a, b) {
          return a.data.id.localeCompare(b.data.id); // sort by ID ascending
        });
    });

    eleventyConfig.addCollection("getAllStandardsOrderedByTitle", function(collectionApi) {
      return collectionApi.getFilteredByGlob("**/standards/*.md").sort(function(a, b) {
          return a.data.title.localeCompare(b.data.title); // sort by title ascending
        });
    });

    eleventyConfig.addCollection("getAllPrinciplesOrderedByTitle", function(collectionApi) {
      return collectionApi.getFilteredByGlob("**/principles/*.md").sort(function(a, b) {
        return a.data.title.localeCompare(b.data.title); // sort by title ascending
      });
    });

    eleventyConfig.addCollection("getAllPatternsOrderedByTitle", function(collectionApi) {
      return collectionApi.getFilteredByGlob("**/patterns/*.md").sort(function(a, b) {
        return a.data.title.localeCompare(b.data.title); // sort by title ascending
      });
    });

    eleventyConfig.addGlobalData("phaseBannerConfiguration", () => {
      return {
        tag: {
          text: "New Service"
        },
        html: 'This is a new service – your ' +
            '<a class="govuk-link" href="/provide-feedback/" target="_blank" rel="noopener">' +
            'feedback (opens in a new tab)' +
            '</a> ' +
            'will help us to improve it.'
      }
    });

    eleventyConfig.addGlobalData('siteRoot', _siteRoot);

    injectGitSha(eleventyConfig, gitHubRepositoryUrl);

    return {
        dataTemplateEngine: 'njk',
        htmlTemplateEngine: 'njk',
        markdownTemplateEngine: 'njk',
        dir: {
            data: '../_data',
            layouts: '../_includes/layouts',
            includes: '../_includes',
            input: 'docs'
        }
    }
};